Gasoline compositions



GASOLINE COMPOSITIONS Eddie G. Lindstrom, Martinez, and Maurice R. Barusch,

Richmond, Calif., assignors to California Research Corporation, San Francisco, Calif., a corporation of Delaware No Drawing. Application February 26, 1958 Serial No. 717,573

'4 Claims. (Cl. 44-66) This invention relates to an improved hydrocarbon fuel composition suitable for operation in a spark-ignition internal combusion engine, and particularly to a gasoline composition containing a unique addition agent which functions to reduce deposits in the induction system of spark-ignition engines.

In certain types of automotive engine service, rough idling and engine stalling has long been a consistent problem and has required frequent carburetor adjustments and reconditioning in order to maintain satisfactory operation. This problem of poor idling operation has been accentuated and expanded with the increased traffic density in metropolitan areas and the use of multi-throat carburetors in private automobiles. It has been determined that a primary factor in poor idling operation is an accumulation of deposits in the throttle body section of the carburetor which causes an over-rich mixture at idle and a reduction in idle speed. The accumulation of deposits in the induction system of the engine and, particularly, in the throttle section of the carburetor is especially pronounced in services requiring considerable idling, such as taxicab and door-to-door delivery service. In private automobile operation, this problem is particularly emphasized in the metropolitan areas where heavy city traffic is encountered with appreciable stop-and-go driving.

The critical accumulation point for these deposits is adjacent to the throttle plate, whose position controls the air-fuel ratio. As these deposits accumulate, the air flow at idle is retricted with no change in fuel flow, and a rich mixture results causing erratic idling and engine stalling. In order to compensate for the presence of these deposits, the throttle must be opened slightly by increasing the idle speed adjustment which, although allowing more air flow, automatically supplies more fuel. This requires a fuel correction by changing the idle mixture adjustment screw a compensating amount. The amount of idle adjustment required to maintain satisfactory idle performance is an indication of the deposit buildup. Furthermore, deposits will often form in the idle air passageway causing restriction which allows the manifold vacuum to draw more gasoline into the engine, again causing rich idle and engine.stalling.-

It has been established that the primary source of these deposits is the contaminants in theintake air of the engine when operating at idle. The greatest source of these intake air contaminants is engine blowby, which accounts for approximately one-half of the deposits. from other vehicles, dust, and other components classed as normal air' pollutants contibute to the formation of deposits.

The hydrocarbon'componentsof the gasoline fuel bear no direct relation to the formation of these deposits; Tests have'indicated that unstable or aged gasolines having a high ASTM gum or high potential gum values produce no greater deposits; than stable, low-gum gasolines under comparableI operating conditions.

States atent G 2,922,768 Patented Jan. 2 6, i960 "ice ' spark-ignition engine with a fuel composition com- Exhaust ,1

In contrast to the periodic mechanical adjustments pounded in accordance wtih the present invention, it is possible to materially improve the idling operation of the engine and sustain this improved operation even under adverse conditions of intake air pollution.

It has been discovered that the incorporation in a hydrocarbon base fuel boiling within the gasoline boiling range of a small amount of an oil-soluble acyclic amino alkylene amide, and preferably an acyclic amino alkylene amide containing an aliphatic radical, such as an alkyl radical of less than 5 carbon atoms, attached to the amino group, will provide a fuel composition which will eifective ly inhibit the build-up of deposits in the carburetor of an engine operated thereon. In addition, a gasoline composition containing this improving agent will substantially reduce and prevent the formation of deposits throughout the area of the air-fuel induction system of the engine.

A particular class of compounds which function as the above unique improving agents may be represented by the following general formula:

in which R is an acylic hydrocarbon radical containing 11 to 17 carbon atoms, A is an alkylene radical and preferably an alkylene radical containing 2 to 4 carbon atoms, and in the two occurrences of R one is hydrogen and the other is an aliphatic radical of 4 and fewer carbon atoms, and preferably containing 2 to 4 carbon atoms; in particular, a C -C -alkyl radical. It will be noted that the alternate positions of the aliphatic radical R in Formula I, are representative of the isomeric'forms of the compound, both of which are normally present to a greater or lesser extent, depending upon the reaction employed in the preparation of these compounds. These isomeric forms may be conveniently referred to as a linear amino amide with reference to the form:

0 Rii-NH-A-NHR (H) and as an amino tertiary amide with respect to the following form:

0 A-NH1 R (111) whereinthe symbols R and A follow the definitions given for :Formula I, and R is an aliphatic radical containing 4 or less carbon atoms, such as an unsubstituted alkyl radical of 4 and fewer carbon atoms. This alkyl radical may be, for instance, methyl, ethyl, n-propyl, n-butyl, sec-butyl or tert-butyl radical.

,The improving agents of the invention may be prepared in accordance with conventional reactions involving the formation of amides. Thus, these compounds may be prepared by the condensation of a higher fatty acid, a salt or anester thereof with N-aliphatic-substituted alkylene polyamines under conditions of reaction such as to control the condensation to the elimination of one mol of water. The higher fatty acid component of the reaction may be an acid, such as lauric, myristic, palmitic, stearic, linoleic or olcic acid, while the polyamine reactant may be a polyalkylene polyamine or an N-(alkylene oxide) derivative of an alkylene diamine. In all in- 3 stances, the alkylene group is preferably an ethylene, propylene or butylene group. Other methods of preparing the amides of the invention may also be employed.

It is usually desirable to prepare or formulate the improving agents of the invention in the form of a concentrate to facilitate handling problems and permit a simple blending operation in the incorporation of the additive in the fuel. In the preparation of the concentrate, the improving agent is dissolved in a hydrocarbon solvent, and particularly an aromatic solvent, in a concentration range of at least percent by weight and up to about 70 percent by weight.

The improving agents of the invention, by reason of their unique effectiveness, are incorporated in the hydrocarbon base fuel in relatively small amounts and, preferably, within the range of about 0.0003 to 0.1 percent by weight. Although larger concentrations may be employed, their effectiveness insofar as the reduction of carburetor deposit build-up does not materially improve with additional concentration of the additive. Those additives in which the aliphatic alkyl substituent on the nitrogen atom is a straight-chain C -C alkyl are preferred, being most eflective in reducing the deposits.

While the foregoing description of the improving agents of the invention are directed to the free amino amide compounds, certain modifications in composition of the agents may be employed to advantage. Thus, the salts of the amino amide with organic and inorganic acids may be used to provide added improving characteristics to the agents and to the gasoline compounded therewith. The bicarbonate salts and the salts of a substituted or unsubstituted acid of phosphorus are particularly desirable, whereas certain advantages may be gained by the use of salts of representative organic acids such as benzoic acid, acetic acid, and lauryl acid succinate, etc. form of their salts and particularly as a multi-functional 4 tilled at 3 mm. pressure without the column. A heartcut product (78.5 grams) distilling at 205 to 230 C. was dissolved in 500 ml. of isopentane, chilled in a Dry Iceacetone bath and filtered, whereupon isopentane was removed by heating the filtrate. The remaining liquid was hydrolyzed with 0.15 part by weight of water for twelve hours at 40 C. Chemical analysis showed the product to be essentially mono-oleoyl amide of N-n-butylethylene diamine.

Example 11 78 grams (0.6 mol) of N-l-isopropyl-Z-methyl-1,2-propane diamine and 169 grams (0.6 mol) of oleic acid were reacted in the same equipment and under similar conditions, except that toluene was employed instead of benzene to provide refluxing and to assist in removing the aqueous distillate. After treating the reaction product in the same manner as indicated in Example I, and hydrolyzing by the addition of 10% of water and digestion at 110 C. for eight hours, the analysis indicated that more than 80% by weight of the product was monooleoylamide of.N-1-isopropyl-2-methyl-1,2-propane diamine.

Example III In this test, a glass throttle body is inserted between the float section. and the cast iron throttle body of a conventional carburetor. This glass throttle body is a section of glass tubing /;-inch thick, approximately 1% When the improving agents are employed in the agent, the incorporation of the additives in the gasoline 7 may vary over a wider range such as, for example, from 0.0003 to 1.5 percent by weight.

In addition to the subject improving agents in the fue composition, other conventional fuel additives may be incorporated. An added factor in the reduction of deposits within the air-fuel induction system of the engine may be obtained by the incorporation, in combination with the subject improving agents, of a non-volatile oil, such as a light mineral lubricating oil or a petroleum spray oil, which functions as a carrier for the deposits dispersed by the amino amide improving agents. Satisfactory results have been obtained by incorporating a nonvolatile oil in the range of between 0.05 to 0.5 percent by volume and have shown effectiveness in the reduction of deposits in the area of the intake ports of the engine.

The following examples are presented to illustrate the preparation and unique deposit-reducing characteristics of the particular aliphatic/substituted amino alkylene amide agents of the invention, in which the aliphatic substituent on one of the two nitrogen atoms is an unsubstituted alkyl radical of 4 and fewer carbon atoms, and preferably of 2 to 4 carbon atoms.

Example 91 grams (0.3 mol) of methyl oleate was added in a succession of three equal portions to 36.5 grams (0.3 mol) of N-n-butyl ethylene diamine in a reaction flask fitted with a fractionating column packed with glass helices. The temperature was slowly raised to 230 C. after each addition of methyl oleate. which formed in the reaction were removed by distillation, a small quantity of benzene having been added to facilitate removal of methanol and water through the fractionating column. The reaction was carried out with stirring. The reaction mixture was held at 200 to 225 C., for an additional period of eight hours with benzene refluxing in the column. The reaction product was dis- Methanol and water inches inside diameten'and about 2 inches long. About -%-inch down from the upper edge, holes are drilled diametrically to receive a conventional metal throttle plate and shaft. The carburetor and engine employed in the test are those of a 1952 Plymouth.

The engine is started with the throttle plate in the cast iron body controlling the speed, and the throttle plate in the glass body wide open. When the engine is warmed up so that no danger of backfiring exists, the throttle in the glass body is made to assume the throttling function, and the plate in the iron body is opened'wide. Two small tubes carry the idle mixture from the float section to appropriate passageways in the cast iron throttle body.

The engine is operated a total of two hours on the test gasoline at about 500 r.p.m. idle, with five fullthrottle, no-load accelerations, up to a speed of about 3000 r.p.m. every 15 minutes during the test period. During each run, all of the engine blowby is piped to the engines air cleaner atop the carburetor. At the end of the test run, the engine is shut down, and the glass throttle body removed and rated in accordance with the degree of deposits on a scale ranging from 1 to 7. A rating of l indicatss a complete lack of deposits with the throttle body clean, and a rating of 7 indicates substantially complete coverage with black, opaque deposits. This test procedure and the rating of compounded gasolines obtained thereby have found excellent correlation with actual test operations in the field.

In accordance with the foregoing test procedure, the following data were obtained in testing the representative amide materials of Examples I and II:

m Deposit Rating I 1 All deposit ratings corrected to a base fuel rating of 6.0.

The base fuel employed was a commercial leaded regular gasoline which is representative of nationallyavailable commercial gasolines. As was previously mentioned, the hydrocarbon composition of the base fuel has a negligible effect upon the formation of carburetor deposits except as it influences the composition of the blowby, and the test results given above on the base fuel will be approximately the same, irrespective of the stability, gum content, or other characteristics of the hydrocarbon components of the fuel.

In addition to the foregoing test data, a gasoline composition compounded in accordance with the present invention was field-tested in representative fleet service and private automobile operation over an extended period of time with periodic inspection of the air-fuel induction systems of the engines and, in particular, the carburetors. In all instances, the test fuel not only inhibited the formation of carburetor deposits, but also was efiective in removing existing deposits within the carburetor and the intake manifold, and permitted continuous satisfactory operation extending beyond periods where, normally, carburetor overhauling was to be expected.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

This application is a continuatiou-in-part of our application Serial No. 424,243, filed April 19, 1954, and

issued as US. Patent 2,839,372 on June 17, 1958.

We claim:

1. An improved gasoline composition which comprises a major portion of a hydrocarbon base fuel boiling within the gasoline boiling range, having incorporated therein about 0.0003 to 1.5% by weight of an acyclic amino alkylene amide of the following formula:

i R- C NANH R wherein R is an acyclic hydrocarbon radical containing 11 to 17 carbon atoms, A is an alkylene radical containing 2 to 4 carbon atoms, and in the two occurrences of R one is hydrogen and the other is an alkyl radical of less than 5 carbon atoms.

a 2. An improved gasoline composition which comprises a major portion of a hydrocarbon base fuel boiling within 6 the gasoline boiling range, having incorporated therein about 0.0003 to 1.5% by weight of a mixture of amides of the following formulae:

RiNHA-NHR and /A-NH2 RC-N wherein R is an acyclic hydrocarbon radical containing 11 to 17 carbon atoms, A is an alkylene radical containing 2 to 4 carbon atoms, and R is an alkyl radical of less than 5 carbon atoms.

3. The gasoline composition of claim 2, containing, in addition, 0.05 to 0.5% by volume of a nonvolatile oil. 4. An additive concentrate capable of incorporation into a gasoline, said concentrate consisting essentially of a hydrocarbon solvent boiling substantially within the gasoline boiling range and having dissolved therein an amount ranging from about 10 to about by weight of an oil-soluble acyclic amino alkylene amide of the formula of R one is hydrogen and the other is an alkyl radical of less than 5 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS 2,014,924 Benedict Sept. 17, 1935 2,312,082 Dietrich Feb. 23, 1943 2,340,881 Kelley et a1. Feb. 8, 1944 2,387,501 Dietrich Oct. 23, 1945 2,508,924 Mertens et al. May 23, 1950 2,568,876 White et al. Sept. 25, 1951 

1. AN IMPROVED GASOLINE COMPOSITION WHICH COMPRISES A MAJOR PORTION OF A HYDROCARBON BASE FUEL BOILING WITHIN THE GASOLINE BOILING RANGE, HAVING INCORPORATED THEREIN ABOUT 0.0003 TO 1.5% BY WEIGHT OF AN ACYCLIC AMINO ALKYLENE AMIDE OF THE FOLLOWING FORMULA: 